Factors effecting expression of vaccines in microalgae.

PhycoBiologics is developing an oral vaccine delivery system using vaccines expressed in the chloroplast of microalgae. Despite many advances in plastid transformation technology, levels of expression remain inconsistent. We have concluded that the main factors affecting the level of recombinant protein expression in the chloroplast of Chlamydomonas are: codon optimization, protease activity, protein toxicity and transformation-associated genotypic modification.

Aberrant epigenetic modifications in hepatocarcinogenesis induced by hepatitis B virus X protein.

Background & Aims: The involvement of the hepatitis B virus X (HBx) protein in epigenetic modifications during hepatocarcinogenesis has not been previously characterized. The aim of the present study was to identify the involvement of HBx in regional hypermethylation and global hypomethylation during the formation of hepatocellular carcinoma (HCC).

Methods: Liver cell lines were transiently or stably transfected with an HBx-expressing vector.

Repetitive-DNA elements are similarly distributed on Caenorhabditis elegans autosomes.

The positions of approximately 4,800 individual miniature inverted-repeat transposable element (MITE)-like repeats from four families were mapped on the Caenorhabditis elegans chromosomes. These families represent 1-2% of the total sequence of the organism. The four MITE families (Cele1, Cele2, Cele14, and Cele42) displayed distinct chromosomal distribution profiles.

Characterization of repetitive DNA elements in Arabidopsis.

We have applied computational methods to the available database and identified several families of repetitive DNA elements in the Arabidopsis thaliana genome. While some of the elements have features expected of either miniature inverted-repeat transposable elements (MITEs) or retrotransposons, the most abundant class of repetitive elements, the AthE1 family, is structurally related to neither. The AthE1 family members are defined by conserved 5' and 3' sequences, but these terminal sequences do not represent either inverted or direct repeats.

Rapid isolation of nuclei from carrot suspension culture cells using a BioNebulizer.

The BioNebulizer is an instrument that breaks cells and large molecules using the shearing forces created by laminar flow of high-pressure gas in the microcapillary channels generated by the instrument. Within 4 min, 90% of the carrot suspension culture cells that passed through the nebulizer were broken. Cytosol and organelles were released from the broken cells leaving cell wall ghosts.